1. Field of the Invention
The present invention relates to storage devices, and more specifically, to a storage device that carries a general-purpose chassis including a plurality of hard disk drives provided thereinto from both of the surface sides thereof.
2. Description of the Related Art
A system handling a large amount of data like a big data center, or other types of centers, performs data management using a host computer and a storage device. The storage device carries therein a plurality of hard disk drives arranged in an array, and manages these hard disk drives by RAID (Redundant Array of Independent Disks), thereby protecting data.
In relation to the increasing amount of data for handling, the number of hard disk drives for mounting in the storage device is also increased. For example, Patent Document 1 (JP-A-2008-47249) describes a storage device in which a plurality of hard disk drives is mounted in a chassis provided specifically for the hard drives.
With the storage device of such a type, the hard disk drives are cooled during a process of flowing air provided from the outside into the chassis over an air-flow path formed inside of the chassis, and the air is exhausted from a fan unit disposed on the upper surface of the chassis.
Patent Document 2 (JP-A-2007-11931) also describes a storage device of a type including a general-purpose rack as an alternative to a specifically-provided chassis, and to the rack, a user sequentially adds a module mounted with a hard disk drive.
The problem with such a storage device utilizing the general-purpose chassis is that a fan for air exhaustion use cannot be disposed on the upper surface of the rack, and the rack cannot be formed therein with an air-flow path. The storage device is thus so configured that a hard disk drive is combined with a power supply and a fan, and the resulting module is accommodated in the rack.
The module is provided into the rack in such a manner that the hard disk drive is facing the front of the rack. The air is sucked from the front of the module into the rack, and is exhausted from the rear of the module.
Even with such a storage device using a chassis of a general-purpose rack type, with the increasing amount of data for handling, the number of hard disk drives will be increased for mounting in the chassis. If the hard disk drives are to be piled up one by one in the chassis, for increasing the packing density of the hard disk drives, the general-purpose chassis has to be large in size so as to be able to accommodate therein the hard disk drives in the height direction thereof.
Instead of piling up the hard disk drives as such for increasing the packing density thereof, it is preferable to insert the hard disk drives into the general-purpose chassis from both front and rear surface sides of the chassis.
The issue here is that mounting a previous modular unit into a chassis from both of the surface sides thereof is difficult due to the large size of the modular unit. In consideration thereof, a fan may not be combined in the modular unit but may be disposed on at least one surface side of the chassis, and may cool hard disk drives disposed in the chassis from both of the surface sides thereof.
If the fan is disposed on the front of the chassis, however, the fan may become an obstacle for an operator of the storage device to perform maintenance and replacement on the hard disk drives in the chassis.
Another problem is that the cooling performance is not high enough for the hard disk drives located on the rear surface side of the chassis. This is because the air passing therethrough is high in temperature as it has been passed through the hard disk drives on the front surface side of the chassis.
In view of the above-identified problems, in the storage device of a type using a general-purpose chassis, the hard disk drives have not been provided in the chassis from both of the surface sides thereof.